The GD25Q40C (4M-bit) Serial flash supports the standard Serial Peripheral Interface (SPI), and supports the Dual/Quad SPI: Serial Clock, Chip Select, Serial Data I/O0 (SI), I/O1 (SO), I/O2 (WP#), and I/O3 (HOLD#). The Dual I/O data is transferred with speed of 240Mbits/s and the Quad I/O & Quad output data is transferred with speed of 480Mbits/s. https://elecena.pl/product/17739871/serial-flash-memory-gd25q40ctigr-4mb-120mhz 2021-04-16 https://elecena.pl/product/17739871/serial-flash-memory-gd25q40ctigr-4mb-120mhz 2025-05-24